A facile, coverage controlled deposition of Au nanoparticles on ZnO nanorods by sonochemical reaction for enhancement of photocatalytic activity
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This study reports the synthesis of Au/ZnO heterostructured nanorods by a facile sonochemical method and their improved photocatalytic activity. A simple and fast deposition of gold nanoparticles on ZnO nanorods was performed without any surfactants or additives. Through various analyses (SEM, XRD, TEM, and EELS), we confirmed the formation of a highly crystalline Au/ZnO nanostructure; several tens of nanometer-sized polycrystalline Au nanoparticles were uniformly deposited on the surface of ZnO nanorods. The size and the density of Au nanoparticles could be controlled by the modulation of the concentration of the gold ion precursor and the solvent compositions. Formation of smaller Au nanoparticles with a lower surface coverage was induced at a lower concentration of the gold ion source with a solvent composition ratio of 1:4 of D.I. water to ethanol. Compared with bare ZnO nanorods, Au/ZnO heterostructures exhibited enhanced photocatalytic activity in the photodegradation of an organic dye, which is caused by the Au nanoparticles acting as an electron sink and lowering the local work function.
KeywordsNanowire ZnO Nanoparticle
This work was supported by grants from the National Research Foundation (NRF2010-0009545, NRF2010-0015975), 2011 Global Research Network Program (220-2011-1-C00033) and by the Korean Research Foundation Grants funded by the Korean Government (MOEHRD) (KRF-2008-005-J00501).
- Ahmad M, Yingying S, Nisar A, Sun H, Shen W, Wie M, Zhu J (2011) Synthesis of hierarchical flower-like ZnO nanostructures and their functionalization by Au nanoparticles for improved photocatalytic and high performance Li-ion battery anodes. J Mater Chem 21:7723–7729. doi: 10.1039/C1JM10720H CrossRefGoogle Scholar
- Chen ZH, Tang YB, Liu CP, Leung YH, Yuan GD, Chen LM, Wang YQ, Bello I, Zapien JA, Zhang WJ, Lee CS, Lee ST (2009) Vertically aligned ZnO nanorod arrays sensitized with gold nanoparticles for Schottky barrier photovoltaic cells. J Phys Chem C 113:13433–13437. doi: 10.1021/jp903153w CrossRefGoogle Scholar
- Lin H, Liao S, Hung S (2005) The dc thermal plasma synthesis of ZnO nanoparticles for visible-light photocatalyst. J Photochem Photobiol A 174:82Google Scholar
- Liu J, Guo Z, Meng F, Jia Y, Luo T, Li M, Liu J (2009) Novel single-crystalline hierarchical structured ZnO nanorods fabricated via a wet-chemical route: combine high gas sensing performance with enhanced optical properties. Cryst Growth Design 9:1716–1722. doi: 10.1021/cg8006298 CrossRefGoogle Scholar
- Wang GY, Zhang WX, Lian HL, Jiang DZ, Wu TH (2003) Effect of calcination temperatures and precipitant on the catalytic performance of Au/ZnO catalysts for CO oxidation at ambient temperature and in humid circumstances. Appl Catal A Gen 239:1–10. doi: 10.1016/S0926-860X(02)00098-4 CrossRefGoogle Scholar